That's actually the thing: When those features were originally announced, people everywhere were FURIOUS about it, here, on steam, all that.

Then after the game was released, most people seemed to have calmed down and even realized that these features are not bad.

I'd still like to see evidence with a grand claim like "people everywhere". People are opinionated shits and you just have to accept that, same with SamVR. Although the problems people have with SamVR don't (mostly) stem from VR but the fact that there was a lack of information (only a few subtle clues isn't a great idea) that it wasn't the announcement of a main installment. It was just poor planning.

Anyway, most of the problems long-time Serious Sam veterans had with Serious Sam 3 weren't based in the slightest on the new gameplay mechanics. It was the monotone visuals, often uninspired enemy scripting, low enemy variation, almost complete lack of funny secrets and some of the new enemies had bad implementation. If all of these problems are addressed in Serious Sam 4 I'm positive most of us would consider it the best game in the series.

__________________"Is there any better Gerüstbaufirmenvorarbeiterschlüsselanhängerfarbenwasserlöslichkeitskontrollchemiker than discy? No!" -Shrinker
[22:30] Fiendian: Discy, Finzy and Louva shall merge into a superentity known as the Lickyfonz.
"Can we just move Discy's posts to the HOF automatically already? :P" -Jetty

If you try to make something that satisfies everyone, you'll just end up creating something that satisfies no one.

As for "people everywhere", you have to remember that the most vocal people are those who are not satisfied, while those who don't have an issue will simply not say anything. So you get to see all the complaints regarding some aspect of the game, but you don't get to see all the people who have no issue with it or like it, because those people aren't taking part in those threads/discussions (or at least very rarely).

All in all, yes, there was an uproar once the "modern" features of SS3 gameplay were announced, there was an uproar when SSVR was announced. You'll always have those. People get hyped, people get disappointed and people simply disagree with some decision/direction.

As Discy said, many of the long-time SS fans/veterans had entirely different critique of SS3 than those knee-jerk reactions, that you get immediately after something is announced or released.